Joint inserts for bridging expansion joints

ABSTRACT

A joint or gap insert for bridging expansion gaps in structures, especially bridges, which includes strip means of elastic material having recess means with an arcuate cross section arranged within that region of the strip means which in installed position of said insert will be located within the region of the expansion gap to be bridged while reinforcing means extend into the strip means and are adapted to be firmly connected to the structure, the expansion gap of which is to be bridged.

nited States Patent [19] Sing et al..

[ JOINT INSERTS FOR BRIDGING EXPANSION JOINTS [75] Inventors: WilhelmStog; Reinhard Springer,

both of Waltrop, Germany [73] Assignee: W. Stog KG, IndustrieundRohrleitungsbau, Waltrop, Germany 22 Filed: Feb. 21, 1973 21 Appl. No.:334,297

[30] Foreign Application Priority pata July 19, 1972 Germany... 22 3541352 us. (:1 14/16,'5 2/573, 404/65 [51] 1111.0. Elc 1.1/ [58] Field 61Search 14/16; 404/64, 65, 68; 52/573, 396, 471

[56] 3 References Cited UNITED STATES PATENTS 3,375,763 4/1968 Welch14/16 3,720,474v 3/1973 FOREIGN PATENTS OR APPLICATIONS 1,051,881 12/19Great Piritain 404/65 H Ill 6 M Jam-w Stog 14/16 [11] 3,822,428 1 July9,1974

3/1967 Germany 404/ 1/1970 France 14/16 Primary Examiner-John E. MurtaghAttorney, Agent, or FirmWalter Becker 1 1 ABSTRACT A joint or gap insertfor bridging expansion gaps in structures, especially bridges, whichincludes strip means of elastic material having recess means with anarcuate cross section arranged within that region of the strip meanswhich'in installed position of said insert will be locatedwithin theregion of the expansion gap to be bridged while reinforcing means extendinto the strip means and are adapted to be firmly connected to thestructure, the expansion gap of which is to be bridged.

4 l2 Clain 1 s, 3 Drawing Figures PATENTEDJUL 9 m4 SHEET 3 BF 3 Fig. 3

2s 63 e1 23 21. 2a

1 JOINT INSERTS FOR BRIDGING EXPANSION JOINTS This invention relates toinserts for bridging expansion gaps in structures, in particularbridges, which inserts comprise a strip of elastic material held oneither side of the expansion gap in grooves provided in the roadway,while in that zone of the strip which points in the direction of theexpansion gap there is provided at least one recess extending parallelto the expansion gap.

With a gap strip of this type there is provided at least one-recess sothat when the strip is compressed it will not buckle too much and willnot be lifted out of the supporttherefor. It has been found, however,that these recesses which usually have a rectangular shape, aresubjected to heavy wear in thevicinity of their corners. Moreover in thecase of relatively long gap strips, the zones lying between? therecesses are lifted off locally from the roadway grooves supporting thevstrip. In this way, dirt and moisture enters between the underside ofthe strip and the roadway groove and are able to reach the lateral stripfastening members. Furthermore, in the case of considerabledeformationof the strip, there exists the danger that its free side faces will belifted off from the adjoining seal compounds or the like. This, too,permits moisture to enter.

It is, therefore, an object of this invention to obviate the drawbacksin the gap insert described above, and in particular to provide a gapstrip which will be able to compensate for a relatively strongcompression of the strip without undergoing any substantial deformation.

These and other objects and advantages of the invention will appear moreclearly from the following specification, in connection withtheaccompanying drawings, in which: 1

FIG. I is a cross section through a gap insert according to theinvention which is relatively narrow, but can expand to a relativelyconsiderable extent.

FIGS. 2 and 3 illustrate gap inserts for a relatively great expansion.

According to the present invention there is provided a gap or jointinsert for bridging expansion gaps in structures such as bridges, whichincludes a strip of elastic material such as rubber material or othersuitable elastic material such as synthetic elastomers. The strip ofelastic material is held on either side of the expansion gap in groovesin a roadway, while in the zone of the strip directed towards theexpansion gap there are provided recess means extending parallel to theexpansion gap, said recess means being arcuately curved in cross-sectionwith the cross-sectional are extending in a direction transverse to thelongitudinal direction of said expansion gap, thereby exerting astabilizing effect on said strip. 1

In this way the advantage is obtained that when the strip is subjectedto compression or expansion, the tensions occurring inside the strip arediverted uniformly to the fastening members provided in the edge zones.The additionally provided stabilizing means aid in ensuring that thedeforming forces within the strip are diverted and anyoccurringdisplacements of the materials will not lift the strip off fromthe bottom of the grooves or from the laterally adjoining roadways orintermediate inserts.

Advantageously, each recess is very shallow.

Each recess may have an eccentric convex shape. In this connection it isadvantageous if in the longitudinal direction of the strip the recesshas numerous consecutively arranged eccentric convexities of relativelyshort linear extension, which are alternately orientated towards one orthe other one of the mountings.

According to another embodiment of the invention, ribs are providedinside the arcuately curved recess, in spaced relationship to eachother, said ribs extending transverse the expansion joint.Advantageously, the ribs form a single piece with the strip.

In gap inserts where relatively high expansion may be expected, theremay be provided two parallel recesses, each being parallel to theexpansion gap. Both recesses may be eccentn'e'ally curved, while domesor arches thus formed are orientated toward the mountings.

Referring now to the drawings in detail, an expansion gap is providedbetween the two parts 11 and 12 of a structure, such as abridge, road orthe like. The substructure consists of concrete and has -a surfacing 13with an asphalt layer 14 which forms the roadway surface. The surfacing13 generally consists of bitumen and rests on the substructure with aninsulating water repellent synthetic material layer 15 interposedtherebetween, More specifically, such layer may consist e.g.,

' of an aluminum foil cemented by a bitumen or other known waterrepellent layer as commonly used in road building. The layers l3, l4, 15do not extend to the expansion gap 10, whereby roadway grooves areformed for accommodating a gap strip. In the illustrated embodiment'ofthe invention, each structural part 11 and 12 has an angle iron 16 whichis parallel to the expansion gap and which has a horizontal flange l7and a vertical web 18. The flange 17 is fastened to the bottom 19 of theroadway recesses by welding it to a reinforcement 20 which is providedin the substructure. A T- piece 22 is, by means of threaded bolt 25,connected to the free upper surface 21 of the flange 17, said T- piece22 having a flange 23 and a-web 24. The web 24 is made inthe. form of arib which extends upwards into the marginal area of a strip 26 ofelastic material. Advantageously, the strip 26 is joined to the rib 24by vulcanization. r

In addition thereto, a resilient angle plate 27 is secured to the uppersurface of the horizontal flange 23 of the T-piece 22 by means of thebolt 25. The vertical arm of plate 27 bears against the free side face28 of the strip 26 under preload, which latter is generated bytightening the nut of the bolt.

In the embodiment shown in FIG. 1, the angle iron 16 has essentially thebasic'shape of an inverted T so that the horizontal flange 17 extendsinto the flange portion 35. The insulating synthetic material layer 15extends to the horizontal flange portion 35 and may also extendupwardlyparallel to the web 18. The space between the resilient angleplate 27 and the vertical web 18 or the adjoining asphalt layer 14 andthesurfacing or cover 13, is, after the bolts havebeen fixed inposition, sealed by sealing compound 29, inserted elastic strips or the7 side faces 28 of the strip 26. Its cross section may be trapezoidal orrectangular or, as shown in FIG. 3, substantially triangular in shape,the surfacing 13 and the asphalt layer 14 being continued up to theinclined side face 72 and if necessary into the recesses 71. In theroadway zone only a narrow band of the section element 70 is exposed,which is provided with a tip or nose 73 which prevents the adjacentroadway surfacing from being pushed up on the face 72. The angle iron 16may be omitted when section element 70 is used, and may be replaced by aplate 76-which is welded to the reinforcing member 20. Within the regionof the expansion gap 10, the plate 76 has a bent-over edge 75 whichserves as a reference edge during shuttering for setting the reinforcingmember 20 in concrete and may be reinforced by a rib. Below the plate 76there may be applied a layer 77 of viscous-elastic synthetic material,e.g. a two-component resin, especially eposy resin, which afterconcreting, is injected through the opening for the bolts 25 between theplate 76 and the upper surface of the structure 12 and when hardened hasapproximately the same hardness as concrete. Any cavities are thussealed and the formation of damp chambers is prevented.

As will be evident from the drawings, the vertical web 24 of the T-piece22 may in certain circumstances be deflected; this is illustrated by theinclined web 24'. In this way, the fixing in position of the strip 26 onthe ribs or webs 24, 24 is improved.

A recess 30 is formed on the underside of the gap strip, and extends inthe direction of the expansion gap 10. This recess has the shape of ashallow curve which in the embodiment shown in FIG. 1 is eccentric.Moreover, with the embodiment of FIG. 1, the recess has in thelongitudinal direction of the strip 26 numerous seriesly arrangedeccentrically arched portions which have a relatively short linearextension. According to FIG. 1, the arched portion 30 is located in thesectional plane, and the arched portion 30' therebehind. The archedportion 30 is offset relative to the eccentrically arched portion 30 sothat its dome 61' is adjacent the right-hand mounting, while the dome 61of the arched portion 30 is adjacent the left-hand mounting. Viewed frombelow, the sloping edges 62, 62 of the arched portions 30 and 30 formribs which engagewith one another like fingers. Therefore, in the eventof the strip 26 being compressed, the material is not only deformed inthe direction of the compression movement, but also transverselythereto. Inside the strip, an- S-shaped main stress line occurs. Thesame applies to expansion of the strip.

It is also possible merely to provide ribs inside the curved recesses.These ribsextend transverse the expansion gap and are arranged at agiven distance apart from one another, which, according to the size ofthe strip may amount to between and 40 cm.

In the embodiment according to FIG. 2, two arcuately curved recesses 30are provided which extend longitudinally with the same cross sectionover the entire length of the strip and parallel to the expansion gap10, i.e., transverse the roadway. The recesses 30 are eccentric, theirdomes 61 being orientated toward the lateral mountings. Inside therecesses 30, ribs 63 are arranged so as to taper trapezoidally towardsthe bottom 19 of the roadway grooves. The ribs terminate somewhat abovethe bottom of the roadway grooves.

The ribs 63 of adjacent recesses 30 need not be in alignment with oneanother. Advantageously they are offset relative to each other so thatwhen the strip 26 is compressed, a deformation takes place, such as hasbeen described in connection with FIG. 1.

The ribs 63 may be provided with rigid inserts, as indicated at 64.These rigid inserts 64 assist in ensuring that when a compression of thestrip occurs, the latter is deformed in an even more pronounced S-shape,if the ribs 63 do not align with one another, or if the ribs 63 are inalignment with one another, the gap strip 26 is pressed in the centralzone between the recesses 30 onto the bottom 19 of the groove.

It is, of course, to be understood that the present invention is, by nomeans, limited to the specific showing in the drawings, but alsocomprises any modifications within the scope of the appended claims.

What we claim is:

1. An insert for bridging a gap of an expansion joint in structuresincluding fastening elements having sides fixed in location and free ofmovement, especially bridges, which comprises preloaded strip means ofelastic material secured to stationary sides of the fastening elementsof structures independently of temperature and having recess meansarranged within that region of said strip means which in installedsupport position of said insert will be located within the region facingthe gap to be bridged, said recess means having an unsymmetricallyarched arcuate cross section with the crosssectional are extending in adirection transverse to the longitudinal direction of said gap andthereby having a middle range of movement with a stabilizing effect uponsaid strip means to hinder lifting thereof in installed supportposition.

2. An insert according to claim 1, in which said recess means have aneccentrically arched contour.

3. An insert according to claim 2, in which said recess means comprise aplurality of recesses of an eccentrically arched shape transverse toexpansion joint, and in which said recesses are arranged one behind theother when viewing them in the longitudinal direction of said stripmeans, the arched portion of said recesses alternately being located ondifferent sides of the longitudinal plane of symmetry of the expansiongap to be bridged.

4. An insert according to claim 3, in which said recess means areprovided with ribs extending transverse to the gap to be bridged.

5. An insert according to claim 4, in which said ribs form one integralsingle piece with said insert.

6. An insert according to claim 4, in which said recess means includetwo parallel recesses extending over the width of said insert strip.

7. An insert according to claim 6, in which each of said two parallelrecesses has a dome-shaped portion and a substantially straight portion,said straight portions being adjacent to each other.

8. An insert according to claim 4, in which the ribs ofhadjacentrecesses are offset with regard to each ot er.

9. An insert according to claim 4, which includes rigid reinforcinginserts arranged in said ribs. I

10. An insert according to claim 1, which includes rigid sectionelements engaging the prelateral surfaces of said strip, and bolt meansextending through said rigid section elements for bolting down thelatter.

11. An insert according to claim 10, in which said rigid sectionelements are under a slight preload for slightly preloading said strip.

12. An insert according to claim 1, in which the width of the arcuateportion of said recess means at a maximum equals half of the lengththereof.

1. An insert for bridging a gap of an expansion joint in structuresincluding fastening elements having sides fixed in location and free ofmovement, especially bridges, which comprises preloaded strip means ofelastic material secured to stationary sides of the fastening elementsof structures independently of temperature and having recess meansarranged within that region of said strip means which in installedsupport position of said insert will be located within the region facingthe gap to be bridged, said recess means having an unsymmetricallyarched arcuate cross section with the crosssectional arc extending in adirection transverse to the longitudinal direction of said gap andthereby having a middle range of movement with a stabilizing effect uponsaid strip means to hinder lifting thereof in installed supportposition.
 2. An insert according to claim 1, in which said recess meanshave an eccentrically arched contour.
 3. An insert according to claim 2,in which said recess means comprise a plurality of recesses of aneccentrically arched shape transverse to expansion joint, and in whichsaid recesses are arranged one behind the other when viewing them in thelongitudinal direction of said strip means, the arched portion of saidrecesses alternately being located on different sides of thelongitudinal plane of symmetry of the expansion gap to be bridged.
 4. Aninsert according to claim 3, in which said recess means are providedwith ribs extending transverse to the gap to be bridged.
 5. An insertaccording to claim 4, in which said ribs form one integral single piecewith said insert.
 6. An insert according to claim 4, in which saidrecess means include two parallel recesses extending over the width ofsaid insert strip.
 7. An insert according to claim 6, in which each ofsaid two parallel recesses has a dome-shaped portion and a substantiallystraight portion, said straight portions being adjacent to each other.8. An insert according to claim 4, in which the ribs of adjacentrecesses are offset with regard to each other.
 9. An insert according toclaim 4, which includes rigid reinforcing inserts arranged in said ribs.10. An insert according to claim 1, which includes rigid sectionelements engaging the prelateral surfaces of said strip, and bolt meansextending through said rigid section elements for bolting down thelatter.
 11. An insert according to claim 10, in which said rigid sectionelements are under a slight preload for slightly preloading said strip.12. An insert according to claim 1, in which the width of the arcuateportion of said recess means at a maximum equals half of the lengththereof.